On Wed, Oct 07, 2020 at 11:28:58AM +0200, Arnd Bergmann wrote:

The only one I have actually given up on is the atomisp staging driver,
which uses an awful hack, copying the x86 implementation of
copy_in_user()/compat_alloc_user_space() into the driver.

That is gross.  Just mark the driver as broken for now.  Linus agreed
years ago that we don't need to work around staging drivers.  But
it would still be nice to ping the mainainers, as they often have
better ideas how to solve the problem.